The present invention relates to a remotely controlled robotic vehicle, and more specifically, to a robot designed for remote inspection of underground utilities and other dangerous or highly confined locations.
There are numerous examples of remote dangerous and/or highly confined areas which need regular inspection and maintenance, but which are not safe for human occupation. Probably the most common example of such facilities is underground electrical utility vaults containing equipment such as high voltage electrical transformers and associated circuit breaker systems and the like. Such vaults can be extremely hazardous areas, particularly in the case of overloaded or faulty transformers, which can burn, giving off extreme heat and noxious fumes, or even explode. Often vaults of this type can be accessed only through manholes, which are often only 28 to 36 inches in diameter. Other examples of dangerous and/or highly confined facilities include large gas utility vaults and radioactive environments, such as nuclear reactor containment buildings, cooling pipes, etc.
It is desirable for such dangerous areas to at least initially be inspected by remotely operated cameras, to determine possible hazards. One solution is to install remotely controlled video cameras at all critical inspection areas within the facility. In a fairly new facility, this may prove to be a reasonable solution, but it can involve considerable initial cost and entail a substantial ongoing maintenance and replacement expense. This is not a viable alternative for aging power networks existing, for example, in major east coast cities in the United States. These networks can include thousands of underground vaults.
Furthermore, for such remote areas which have been in continuous use for long periods of time, retrofitting the areas with cameras can be as dangerous or more so than physically inspecting the facilities. These areas are often partially flooded and/or muddy and dirty, such that cameras would sometimes be adversely affected by the environment due to long term exposure. Finally, it is not always possible to predict the particular areas of a facility which will need inspection, and providing video coverage of every square foot of a facility is practically, as well as economically, infeasible.
Another solution is to use remotely controlled, mobile camera carrying vehicles which can inspect and, in some instances, even perform some minimal repairs. While various types of robotic devices that are remotely controlled vehicles are available, one major drawback is the limited ability of such vehicles to operate in the required confined spaces while being able to traverse obstacles. Many prior art vehicles have the ability to traverse obstacles by use of track type driving mechanisms, but they are normally relatively large and do not fit through manholes nor are they able to maneuver in the tight confines in vaults of this type. Other types of robots have existed that are three or four wheeled and which can turn easily and maneuver in fairly confined spaces, but these robots cannot traverse obstacles. Often they cannot traverse obstacles as simple as a ramp, uneven pavement or obstacles such as paper, boards, etc. In accordance with the present invention it is desirable that vehicles must also fit through small openings such as manholes. In addition since the inspection vehicles of the present invention must often run on batteries, it is desirable that such vehicles have low energy demands. Because tracked vehicles and four wheel skid steer vehicles lose a large amount of energy to friction during turns, it is desirable to avoid vehicles of this type.
Many underground electrical installations, particularly in older cities, have been in continuous use for several decades. In some instances, transformer vaults and related equipment have not been inspected for years and sometimes not since their initial installation. In such facilities, construction debris, ceiling and wall material, and other obstacles litter the facility floors. As noted above existing remotely controlled vehicles are simply incapable of both traversing the obstacles and operating in such confined spaces. Of course, should a remote vehicle tip over in an inaccessible or hazardous location, it would be difficult to retrieve it or could create an added hazard to a human.
Accordingly, a more reliable and stable vehicle is needed for performing inspections in remote facilities which have confined spaces and/or hazardous conditions. Such a vehicle should be capable of being reliably, remotely controlled to operate in tight or confined spaces, should be extremely durable and reliable and should be capable of traversing obstacles without danger of tipping. At the same time, such a vehicle should be relatively inexpensive, have relatively low energy consumption and should preferably be of an adaptable, modular design and thus be capable of performing a wide variety of inspection and repair tasks. The vehicle should also have the ability to access an area to be inspected through a manhole.